Distress traffic is the communication（）between the station in distress and the ships, aircraft, coast radio stations, coast earth stations and rescue centers participating in the rescue work.

A . horizontal motion of a white flag B . letter K in Morse code given by light C . code flag S as a hoist D . firing of a white star signal

A . Distress messages should first be transmitted on 2182 kHz B . Channel 16 (156.8 MHz) may be used for distress messages C . If no answer is received on the designated distress frequencies，repeat the distress call on any frequency available D . It is advisable to follow a distress message on 2182 kHz by two dashes of 10 to 15 seconds duratio

A . TE label， IGP label， VPN label B . IGP label， TE label， VPN label C . TE label， VPN label， IGP label D . VPN label， IGP label， TE label E . IGP label， VPN label， TE label

A . A large FTP job is in process.  B . A network interface was misconfigured.  C . The ping command is being used excessively.  D . A bad network interface card and/or network cable is in use.&e

A . MF/HF B . SART C . EPIRB D . any of A, B, C

A . white B . green C . red D . yellow

A . video conferencing traffic tends to be much more bursty in nature and is more prone to have an impact on other traffic flows B . latency requirements are less stringent for video traffic than for voice traffic C . video traffic is less sensitive to dropped packets than for voice traffic D . video traffic requires the retransmission capabilities of TCP whereas voice uses UDP E . video traffic tends to be much more bursty in nature and is more prone to have an impact on other traffic flows F . voice traffic requires the retransmission capabilities of TCP whereas video uses UDP

A . easy/reliable B . difficult/cheap C . stable/compulsory D . easy/expensive

A . No action is necessary，as the DSC control unit will automatically switch to the NBDP follow-on communications frequency B . The operator should immediately set continuous watch on the radiotelephone frequency that is associated with the frequency band on which the distress alert was received C . The Operator should immediately set continuous watch on VHF channel 70 D . The Operator should immediately set continuous watch on the NBDP frequency that is associated with the frequency band on which the distress alert was received

A . IPSec in tunnel mode B . IPSec in transport mode C . GRE with IPSec in transport mode D . GRE with IPSec in tunnel mode

A . common communication system B . distress traffic system C . basic concept of GMDSS D . SAR operation procedure

A . relevant to B . relate to C . in response to D . in relation to

A . The voice traffic cannot be forwarded to the distribution layer. B . The voice traffic cannot use 802.1p priority tagging. C . Port security cannot be enabled on the switch that is attached to the IP phone. D . Quality of service cannot be applied for the voice traffic.

A . requires access lists to identify the voice traffic  B . can allow traffic from a device without 802.1X authentication, by MAC address C . can allow traffic from Cisco IP phones by listening to their CDP advertisements D . allows all packets marked with a ToS of 5 to bypass authentication E . allows all IP voice packets to bypass authentication via stateful inspectio

A . TE middle point B . TE tail end C . TE head end D . All TE nodes along the path E . Independent server

A . double frequencies B . single frequency C . dedicated frequency D . multiple frequencie

A、arrival B、proportion C、scale D、occurrence

A . Smoke signal B . Flash signal C . Fire signal D . Radio emergency transmissio

A．common communication system B．distress traffic system C．basic concept of GMDSS D．SAR operation procedure